Japanese imports and exports crashed by their biggest margins since 1957 last month as the world stopped buying what the country makes best — cars, semiconductors, electrical machinery and ships.

In addition, said one leading economist, the time has come to throw out once and for all the widely-held idea that Japan is a nation of savers — the economy has changed too far and too fast for that to remain the case and in the face of outright crisis, the savings rate may already have turned negative as households dip into their nest eggs.

Analysts described the startling government figures as evidence of Japan’s “canary in the mine” status — it has become a highly sensitive barometer of the global recession and the January figures showed that the crisis has dramatically extended its geographic reach.

The 45.7 per cent year-on-year collapse in exports was the fourth consecutive monthly drop but by far the steepest. Most analysts had guessed that the 35 per cent plunge recorded in December would be convincingly outstripped but the news, said traders, “heightened the sense of crisis”.

The trade deficit plunged to a 29-year low of Y952 billion (£67 billion), with exports to the US registering a record drop of 52.9 per cent. The yen fell on the news, hitting a three-month low of Y96.91 against the dollar. Traders at Nomura said that the yen, after months of bolstering by the unwinding of the carry trade, was rapidly losing its image as a safe haven currency amid global financial turmoil.

Hiroshi Shiraishi, an economist at BNP Paribas, said that Wednesday’s data would serve to make people everywhere realise how much trouble the Japanese economy is in.

The nosedive in car exports was the most spectacular. The sector accounts for about a fifth of all Japanese exports and the falls were catastrophic compared with January 2008: down more than 80 per cent to the US and nearly 70 per cent to Europe. Even previously more supportive regions, such as the Middle East and Russia, stopped buying Japanese cars at a record pace.

Within Asia, the pace of decline in semiconductors, chemicals, cars and steel painted a dismal picture of how badly the region has been hit. Whereas the decline in Japanese exports to the US and Europe reveal the acute downturn in consumer activity, exports to Asia expose a much wider collapse of manufacturing and private consumption.

Kyohei Morita, an economist at Barclays Capital, said that the recent strength of the yen had made an enormous impact on the January data but that equally striking was the sharp 31.7 per cent decline in imports — a phenomenon caused by the sudden deterioration of the domestic economy and the general slide in commodity prices. Critical was the “need to discard notions that Japanese households have a high savings rate and that Japan is a trade surplus nation”, he said.

Japanese savings rates turned negative in the first quarter of last year, according to the Barclays analysis. The change reflects the fact that many Japanese do not have permanent jobs, that people are drawing on their savings and that the long period of low interest rates and extremely modest returns is finally starting to hurt the average household.